i have an exhaust system coming in... I wanted to do some logs before i flash a stage 2 map. i hear these 02s are able to get an exhaust on them and drive without needing an ecu tune. Anyway having the catted uppipe makes me weary seeing as the car has a little over 140k on it. I may run the stock rom on it with the exhaust system to see if it will get rid of the noise.